Our exploration of the West Mata Volcano during our first two dives yielded exciting new discoveries of active volcanic eruptions, exploding hydrogen, high-temperature venting, and lava flowing downslope as newly-minted pieces of rock debris fell like rain around our vehicle, Jason-2. Normally, venting water contains nutrients that feed thriving oases of diverse forms of life, including large tubeworms, clams, mussels, and crabs. However, at West Mata, there is a notable absence of any attached or even “slow-moving” animals on the seafloor- no tubeworms, no clams, no mussels. The active creation of new seafloor and volcanic activity may prevent these animals from ever establishing themselves here. In fact, even highly-mobile animals like crabs have not been observed (and only two fish, so far). Interestingly, so far, the diffuse venting fluids (~5 to 25°C), issuing through cracks and crevices around the eruptive vents, play host to only one type of vent fauna - shrimp. Hydrothermal vent shrimp are known to inhabit vent sites throughout the world. The two species we have encountered are abundant (analogous to the density of microwave popcorn kernels strewn over a sofa), apparently grazing on microbes growing on the rocks and in the venting fluids, and they appear to be similar to shrimp seen at known vent sites a few thousand kilometers to the south.
Our subsequent exploration of the Northeastern Lau Spreading Center (NELSC) has yielded two active vent fields that host foot long tubeworms, mussels, crabs, several species of small snails and shrimp, as well as vent-endemic fish. While our round-the-clock processing of these collected animals (now more than 700 individual animals from more than 14 species) is less than 48 hours old, our initial examination of these animals suggests that we may have collected organisms that may best be described as new species. One thing that is certain is that each dive has yielded new biological discoveries. As I write, we are planning our third dive to explore the eruptive West Mata volcano for additional biological communities.